One-man road grader



May 20, 1930. L. T. KlNcA'NNoN ONE-MAN ROAD GRADER May 20, 1930. L. T.` KINCANNON 1,759,647

ONE-MAN ROAD GRADER Filed May 3, 1927 5 sheets-sheet 2 61H0: ump

. May 20,1930.

' L. -T. KINC'ANNON 1,759,647 ONE-MAN OAD GRADER Filed May 3, 1927A n 5 Sheets-Sheet 4 May 20, 1930.` T. KlNcANNoN l I 1,759,647

oNE-MAN'ROAD GRADER lFili-:fd May 3, 1927 @Sheets-Sheet 5 preferably oil` or Patented May 20, 1930 UNITED STAT Es APATIENT 'ol-FICE LEO T. KIN CANN ON, OF BUCYRUS, OHIO, ASSIGNOR T0 MARIONv MACHINE, FOUNDRY SUPPLY COMPANY, or MARION, INDIANA,

A CORPORATION ONE-MAN ROAD GRADER Appliation nl ed May 3,

The yone man grader, so known lto those versed in the art of earth lhandling, and road grading, is an important implement combin-l ing atraction unit and grading attachment including a scraping appliance and scarify-` mechanism for the grading devices, certain' novel steering mechanism. for the implement, andV other features of limprovement that will more fully appear.l hereinafter. -f l Dealing With'the grading. mechanismy of t 1e means and scarifying `means .havebeen'im dependently supported,` provision being madefor adjustment of the scraping means to vary theangl'eoffoperation thereof, as.

Well as its elevation. My invention contemplates provisions for controlling. they ad-` justments vto desired positions of bothv the scraping and lscarifying instrumentalities employed. My invention further contemplates, broadly', the employment ofy a con trol mechanism by which I am enabled ,tov quickly adjust :and maintain -desired adjust- Vments of both thescra'ping and scarifying means in a unique nianner,'provisions being made 1n this respect for. simultaneously raising or lowering the y"scraping and scarify-v ing means at corresponding ends thereof,

and for independently'adjusting ,the elevations ofthe opposite ends of said`means at Will.y Simultaneouscontrol of sera ingand ore been,

scarifying devices hasnever hereto achieved sofar as I. am advised. V

My invention, yin relation to the'grading feature thereof, further contemplates the control of adjustments ofthe scraping and sca-rifying'devices by afuid pressure means, a suitable liquid, special novel valve mechanisms forming a part of the control means, to enablequick and ready operations off' the earth aforesaid, in 'obtainingthe desiredadjustv yments thereof required in the use ofthe one man grader. v

My inventionincludes r`a ynovel mounting scraping means for facilitating their adjustments aforesaid,

T he steering mechanism of my invention implement, heretoforel the scrapingy Iin section,

Working devices 1927. semi No. Y188,525.

is designed for simplicity of operation and f construction and to enable the proper shiftmg ofthe steering Wheels for steering purposes, with differential movements to impart thereto the proper varying angular adjustments requisite i'nperforming turning movey ments of the' machine, so that the wheel at 'the lnner side of the curve ou which the turn is made will have a greater angle than that on the outer side'of the curve.

l/Vith the foregoing inv view the accompanying drawings illustrate a preferred emhodiment of Ymy improvements, and in thesej drawings: y

Figure l is a side'elevation showing the general construction of a one man grader embodying my improvements.V

Figure 2 s atop planV vieW of the frontv Figure 3 is a view in elevation, u i showing primarily the valve control levers and connections. a somewhat diagrammatic plan mechanisms Figure 4 is Viewv illustrating arrangement of' conduits or pipes, valves, etc., which control and 'conduct the flu-id pressure medium to the cylinders containing the lifti'ng 'and lowering pistons.

Figurel 5 isa cross sectional view through one of the selector valves, taken on about the line 5 5 of Figure j L .l Figure 6 is a vertical sectional view o n the portion of the machine, at Which are located the new featuresv for WhichI claim a patent.

and partly line 6-6 of Figure, through vthe master` valve mechanism,fand showing clearly 'the special relief valve employed.

Figure 7 lis a 7-.7 of Figure 6.

lsectional vievv on the line Figures 8 and 9 are sectional vievvs on the lines 8f8l and 9-9, respectively, Vof Figure 7.- Figure l10 is a fragmentary sectional lview on 'the line 104410V of Figure 6.

Figure ll1 is a sectional rview on the line ll-lloffFigure 6 looking in the ldirection"y of the arroWs.A f

Figures 12and 13 are front andtop elevaf".

tional 'views' showing certain 'steering parts and illustrating particularly the differential shift actions of the Vlinlr connectionslfrom the' main-steering arin.`

Figurer? 14 lis a diagrammatic View, "With leo illustrating the movements of:

the valve levers and resulting adjustments ot the scarifying and scraping Ielements thereby. l Y My one man grader in general forni is of a known type employing a grader attachment associated with or one or more known International 10-20, and Inthe Foi'dson,

adapted to 'be vapplied to types of tractors, such as ternational -30, butthe invention is adapted for use in connection with grading imple.-

mcnts generally,

type or not.

In Figure 1 th whether of such particular tract-or isycomprised of the well known features including the'rear axle 1, rea-r lwheels 2, engine 3, engine housing 4 and front axle 5, with front wheels 6. In applying my grader attachment of the one'man. type the attachment comprising the sides or beams 7 is mounted upon the wheels 2 and 6 in largelythe known manner, the front axle and wheels 5 and 6, respectively, being detached from the body of 'the tractoi' and secured to the front ends of the sides -7 of the' gra-der attachment, the sides 7 being 25 provided with a depending yoke 8, to receive and support the main tractor structure at ,the front end'ofV the engine housingfl'. VThe rear ends of the sides 7 o the grader are mounted 'upon the rear of the al, and the fea tures tractor, structure, as usution ofthe traction means are known, being largely as usual, and

arev immaterial to Vthe invention so they are not described. ,Y My l,steering means includes the'front .axle 5inentioned above, having the usual' stubv operated from 13, the latter having inclined actuating able castings at the 9 which are thereof from piston rods tion of lifting and lowering devices.

" with the front casting/30 of the ment frame castingr 30, passing through the yoke'29', havthere being a springl nut and theV yoke Y '29. Any suitable numberof jscarifier teeth blade circle 21, which enables horizontal angular adjustments of the blades to be madel and ixed'by suitable lock pin means 22, not a part of the invention. The moldboard beams 23 have attached thereto a cross beam 24 made [up of anglefmembersfor rigidity and sustained by suitable couplings 25 at the ends d 26 having the func- My scaritying means comprises thefusual scaritying teeth 27 supported upon a crosspiece or casting 28, the latter connected at its front portion with a curved drawbar or yoke 29.- The yoke 29 is yieldably connected Y grader attachby al draftbar 31, securedto the ing a nut on its rear end, interposedV between said 27 Vrmay be employed, vas needed. The opposite ends of the crosspiece 28which supportV l they vscarifier teeth areV connected with piston rods 32 leading f disposed in cylinders 33, which are pivotally which lead down of the control ot opera- 1 y the customary steeringshaftV 10 and wheel 11. The steering shaft 1() operates ay worm 12, engaging the worm gear the somewhat vertically shaft 14 journaled in suitattachment frame, including the sides 7. The shaftV 1-1 carries the main steering'arm 715,' thel lower endvof which vhas a head-15 Acon-Y nected by ball steering links 17 that lead -tostubvaxle steering arms .9. pai'ts'15,.15f, Vfrom Figures The manner of operation of the` 17 and 9 is 12`and 113, the peculiar shitting 'movement ot the head 15am on an arc and its peculiar l connections the obtaining'of each'arm 9,/ than swing vthek wheels Y angularity almost self evident tothe arms9 enabling that of the other arin,to Y6. ,to different. degrees of respecting, the axis of` the whole vmachine', jas required- 1n turning.

Nowreferring to my gradingrfeaturesand .the means-for controlling adj-ustmentsthereof.. which are `especially novel', Vthe gradingv features include theearth working-devices mprising thescraper thelmoldboard 19. supported by j thew'usual way,

blade 18, carried by front.` endA of the graderV similar Vjoints, 16 with theV the if greater movement of The parts 18 and 19 areY drawbar meinbers'20, niuchV through tlieprovision of the :of the scraping means ,mechanisnn which I n Mounted transversely of the frame Vof my" f l I Figures l, 2 Sand 3, is the valve mechanism and its control Said mechanism includes a master 1 V14 entering the casing 36 supported by yokes 34 suitably' secured to the downwardly from pistons f sides of beams 7 ofthe attachment frame. v

YAll of the cylinders` there are four,are'" Y mountedV otal manner upon @ifV which or certain of them operatedtogether, the ends porting means V28 may be' separately raised and lowered, ort-hey may together. VFor these purposes and lowered I in the sainefpivthe trame 'or sides 7 of the machine and it will be evident that if the pis- Y ton rods 26V and 32`are individuallyoperated,

18 and sc'arifier suplThe piston rods 32are similar to the rods 26 I from cylinders 35 and supn be raised together 'L los provide certain novel'specially designed valve v now describe.v

grader attachment, as seen in llle 311s.

valve A comprising a casing 36, ingwhich are mounted' two overlapping and 38, and apressure relief valve V39. At

the opposite sides of the master valve A are.

selector valves B and C Comprising casings 40, of like form, in which are disposed rotative tively. vThe valve vmembers 41 and 42 arealike master valve A may only be rotated, the valves `valve members 37V `vand sliding selector valves 41 ands42, respecs B and C are-both rotative and sliding, as previously stated. The valve B has its stem conl nected with the lever43by which lever may beV rotated and vcaused to slide in its casing.v The lever L13 a n v has a square stein n troinone side and engaged in a square vopening in the vvalve member 37 of the master valve'A. "Thelevei"l 43,' therefore, is adaptedtofcontrol boththe Y valve member 37`a1id theselectorvalve member 41 Valve 42 is connected by 1ts stem with -a lever y45 corresponding"with lever 43 and also the lever 45' isconnected with the valvemember 38 of the masterv valve VA by toward and tromA each other; A.

The arrangement vof the valve lmeans ]ust described in relationl to the several cylinders 35 and 33 is shown in Figure "4. 'At the rear end of the machine Ip'rovidea fluid pressure pump 48, which maybe operated'from the* engine 3 of the tractor, and is adapted "to constantly pump oil or a similarliquidthrough` the piping system to conduits which lead from' .y the pump to the valves A,B' and Gland the cylinders 33 and 35, and back from the 'valvedevices to'the pump again.` The oilconduits from thepump tothe valve A, connected also with pressure reservoir 48, areishoW-n inFig- Y pipes leading from lthe master valve A totheselec-f tor valve vB are designated'l and 52.' 4Also vthe corresponding conduits from'v the valve ure 1at-49and 50, Theco'nduits or to the valve ,C are designated 53 and 54.

nected to the top of the front scarifyingco'ntrol cylinder 33 'by the pipe V55 and tothe top 'of the rear scraper control cylinder' 35 by thepi'pe 56. Likewise the lower iends ofthe cylinders 33 and 35, `just mentioned, are connected bypipes 57 and 58, respectively, to thecasing `of the valve lB. ,'The samel conduit' or pipe arrangements connect the valve cas-l ings of selectoryalve v@with the other scariier control cylinder 33 and 'scraper `control cylinder 35y and I havefdesignated the corre-A sponding conduits by the same reference char acters with a prime markv associated there- The construction of themaster valve-is peculiar. Its'casing has the oil inletport a and the oil outlet port The valves 37 and 38 have similar ports a always registering with the port a, and similar other ports j adapted to register under proper conditions with-the port b. .The casing 36'hasl are'lief-passage or by-pass n, one end yof which communicates with the entrance port a under all conditions,

n and ,mayl communicate with a second by'pass m by action of the relief ballvalve 39 which is spring pressed by vspring 60.- `The second by-pass m always communicates with the outlet port vThen ythe master valve is in its normal neutralposition the oil pump through the pipe ofthe conduit system passes through the valves 37 and 38 by movement entering the valvevA at port (z, passing through to ports a and having'egress through'the'poifts j, jv, andb.v ,v y l' The valves 37 and 38 have other byspasses that cooperate with certa-'in by-passes in the valve'casing 36 in a manner which will laterv be set forth in tracing the flow of the oil.

The master valve A has three functions; "namely, first, to relievev thev pump pressure when the pump is not needed; second, to de-` liver the oil to the selector valves for upward 4'and downwardstrokes 'of the pistons onv the v right side ot' the machine, and for upward and-downward strokes of the pistons on`the left side;`third, to deliverthe dischargedoil lfrom the cylinders to the reservoir. Refer ring to Figures 5 to v10, inclusive, these various func-tions of the master valve' will be eX- emplified. v f

vFor relieving the pump pressure when. it is 'not' needed,the oil. enters the casing 3(3at a andzpassesv through the valves 37 and 38.bv means ofthe two ports a and out of the cas.- 1 ing through the port-s y', j and Z) back to the reservoir/into which the yoil'is pumpedJ by thel pump 48,said reservoir being-.designated 48, and a const-ant flo-w being thuscinaintained. f

vlVhe'n desired to deliver oil or pressureA medium to the selectorvalves to control upward or downward-strokes of the pistons in the cylinders 33 and 35, the following action takes place; when either of the valve members Y 37 and 38is rotated by its connectedlever 43 Thecasing of the selector valve B` 1s ,con-

with the port d, and the latter is connected with the-selector valve casing at s bythe pipe 51. YIt will be seenvthat the s* side of the valve B is connected with the lower ends ofccertain cylinders 33 and 35, whereas the s side of the valve Bis connected with the-upper ends of certain cylinders 33 and 35. The foregoing *description applies equally well to the valve 38 and its method of supplying the oil to the s and s sides of the valve C, which cooperpates to control the o-il deflection into the conduits leading to thev upper and lower ends of the 'other or remaining cylinders 33 and Thus by moving the valve member 37 in one direction or the other by its lever 43 the left hand ends or right handjends ofthe scar'ifiers supportand scraper blade atthe left side of the implement may be raised or lowered. Likewiseby movingthevalve member 38 similarly by its lever 45 the corresponding op posite' ends of the right hand scariiier support and scraper device may be raised or lowered; In both instancesthe levers 43 and 45 vwill be rotated in planes lengthwise to the machine, andif both levers 'aresimultaneouslymoved in their neutral planes the scraper VILO ' mult-ane ously;

blade and scarifiersupports may beraised siv movement of the levers in the opposite direction'will lower the same simultaneously at corresponding ends. LIfa lever 43er 45V,- as the caseiinay be, is rotated toset the master valve member operated thereby andl thensmoved pivotally to the right or left, asy preselectively desired, the piston in the proper cylinder for moving the-scraper blade means simultaneously,

downwardly or upwardly at 'one end, or the scariier teeth support upwardly or `downwardl at one end, will be subjected tothe ac-v tion o the oil to` accomplish the desired result. I obtain a special nicety Vof control of Vthe movements of thepistons in the cylinders', or independent movement' of such pistons, to raisethe ends of the or lower them simulf taneously, or move one of them at either end,

alone byV reason of the two levers 43 and45'l and their capability of being rotated in 'neu-y tr'al planes longitudinally ot' the machine, or

I both rotated insuchplanes Vand Ypivotally moved either to the right orleft in a plane transversely ofthe machine. Y Y v -As seen in Fig.Y 9, -whenthe port h of theV valve member v38 registers with the ports c. and d', Fig. 9, the oil asV delivered by the pump must pass either through .these-registering 'ports lor pop off through the reliefvalve39 by way of the passage of Ythe by-pass n and passage/:aback to the reservoir.

To enable'.t-,heirmaster` valve to'. discharge I the` oil from the c. 'linders to the reservoir- 48,

- connected/.with portb oil dischared from handfcylin if the valvejm'em er 3 7. is rotated 30 'clocks wise, see-Fig. 6,"the port h thereof, see Fig. 8, willregister with .t e port dandpassage 0 with boththepassages, Gand p2 Passage c is bythe passage m.. The Vthefbottom' of the left ersmay lHow back to the reservoir 48 thi-.ongh-ports or'passages 0,0, p, m and b.

.. scarifier cylinders VThe other. vf movements Vof ockwise and; vcounter-'clockwise.Y es-4 be detailed(V because that'above prese'ted is explanatory of. them all.` i

` The function of the selectorvalves B and C, Figurei3, is obviously to control the deflectionvv of passage of the .oil toeither the i 33 or to thescraper blade cylinders 35,'orrto bot-li. The valves 41and I42, the first of which is shown inFigure Y5, andk them, areprovided withV typical of botliY of passages fw and Hv, and these overlap 'the'. en-

tering ports?1 and t, seeFig. 4, and fr and t',

Y` thus makingitpossible to yraise or lower the scraper 'blade and scarifier atthe same time,

i 6o theV same time ifV the passages Y r and t" at once, and

scaiitier: and scraper mind the somewhat Varm 15 is in a diilerent f the plane in which the connections of the links u the Vvalves 37 and.

.38, the ya e237; coiiii'terclockwise and the .valve as y tablis'hisimilar connections .which rneed 'not the other ports bysiinilarV pipes or conduits i* as seen in Fig.

The operator of the niacliineusually stands .i i i i upon a platform 61, aboutat tlieniiddle poi'- tion of the frame of the machine, and from! 45 'are easily this position the levers 43 and manipulated, as well as the steering wheel tor. Thus Vunder the immediate coiitro1 of the operator we have the 'easy'manipulation and the various control levers for t e tracand adjustment ofthe scarifying and scrap- K ing appliances, because the same ticular manual .labor and most instantly -by the mere ytouch of a control valve lever.

40 is formed with .a .by-pass mitting oil to Vpass 41 or 42, as the Vcase after, a well knownl manner, trapped. l Y f More speciically settin action of my may be, to the other side diagrammatic views of and this is especially true 'Y doesnot involve any par:V

will be eifectedal-f The inner wall ofeacli selector valve casing Y kgrooves-.0", perv from oneside of the valve f sa fand not lbe forth the ez/ractY Y steering mec anismeliavmg in y Figures 12 and 13', it should be observed that `while the steering'wheels are set Jfor straight Y Y ahead travel of the grader, the point of loonlnection of the links 17 horizontal plane fprom 17 with the steering arms 9aie located.n The between the links 17 and the steering arms 9 iis indicated at 12, while the .plane in which the common connection betweenrtlie twoflinks 17 and the main steering arm 15 is'rlocate'd with the'mainv steering 9b Ahorizontalp'lanecontaining the connection Y when the arm 15 is projecting straiglitfor-V wardxor inother words-'while the grader is f V traveling straight ahead, is indicated at e129,

With the parts as shown in Vfull lines inFign ure 12,7both steering wheels filare parallel to 1 enthe I grader* isY traveling each other as w straight ahead.

ing devices having a stub axles carryiing rigid .axle with vpivoted the wheels,

necessary in order to peimitthe wheels to properly track, to slightly angle 'the wheel on the inside of the turn withrespect to the outside. wheels. i I have provided the unusual construction as shown.

In order to accomplish this,

As welljknown with steer.-Y

11C f Whenit" is desired to negotiate Va curve'or turn, Vit is;V a f Since the shaft 14`carryiiig the vsteering' i arm 15 is inclinedwith respect to the two horizontal planes 12a and 12b, any rotation ofthe shaft 14 in eitlier'dir'ection will cause the extremity of the arm 15 connecting the links 17V to move in an inclined plane.

plane intersects the horizontal plane 12a and Vconsequently any movement of the steering yarm 15 will causefthe contiguous ends of the links 17 to approach the plane 12a.V The outer ends of the linkslx' being located in the plane 12a, always remain in this Thisinclined Y 'i axles and their connection with the varms 9 y As well known ingeometry, a straight llne is the shortest distance between twopoints. as the wheelsof the' and for this reason, grader are angled horizontally by the steering arm 15 the two rigid links 17 which are' normally inclined with respect to each other tend to straighten 'out or approach a'straight horizontal position which produces a'lela-` tive separation of the ends of the links Aand consequently the Wheels connected to the links 17, through their respective arms 9, are

' no longer in parallel relation but are angled ture of my invention.

valves supply iiuid pressure with respect to each other, the wheel on the; so to speak, being angledi inside of the curve, greater with respect tothe longitudinal axis of the grader than the outside wheel.

eferring again to steering arm 15 is turned to the left fromlthe point 12c to the pcint12d it also-moves vertically from the plane 12b to the plane 12. The inclined connecting links these figures, causing'a relative straightening out of the links, the extremities12t and12g to move the distances 12h quently the wheel on the lefts'ide of the machine will be'angled greater-than the wheel on the right side since the distance 12l isr greater than 12h.l This is an'important fea- Having thus descriloed'my invention, what I claim as new and desire to securebyLetters Patent of the United States, is

1. In 'a tractor grading machine, inv combination, a frame, supporting and steering' Wheels therefor, a pair of earth working implements associated with the frame ranged transversely thereof, cylinder and said. earth' workingk nected thereto at the ends, fluid pressure supply means communicating with the cylinders to act upon the pistons therein, and control valve mechanism including a whereby the master valve supplies fluid pressure to the selectorfvalves andthe selector to the' cylinders.

2. A machine as set forth .in claiml in.- cluding lever control means common to the master and selector valve means.

3.' A machine as set forth in claiml including lever control means common to the m'aster and being comprised ofseparate valve members, said valve members'being associated for cooperation with one another and each valve member having control of one of the selector valves to govern the action of the latter, in

addition to operating to supply the fluid presconnected up sure medium to said valve.

Figure 12, when the" medlum' to the the pressure *the selector valves ,functioning to supply the, 17 are moved from j the full line position as shownin the figures referred to, ,to the' dotted line positions in vmsm orearth workingimplements, compris-r angular re1ati0n-between' "lng, a. SGIlGSf plStODS-.l'ld' hailing and 12, respectively; 'conseter valve controlling ysure medium to'either or bothof the selecand and ar- 'valvesl'controlling :the ypassagev ends of lcertai n.cylinders,

master valve and separate selector valves with connectlons 1 selector valve means, the master valve 4. Ina tractor grading machine, in coma supportingframe, spaced 'earth f working implements'arraiiged,onein advance 1 of the other, carryingfme'ans forfthe imple- 'l vments on said frame including hydraulic cylinders and pistons operating therein, the latter connected`with oppositefends of vthe earth working implements,'. simultaneouslyor independently'raising corresponding ends of theeath working implements vincluding a pressure ymedium supply '-leadingtojI the cylinders and control means for said pressure medium includinga master valve composedof complemental valve .mem-

bers and i selector valves associated`- with the rmaster valve, the maste upon the pistons in the cylinders. y 5. 'An hydraulic operating control mechasuspension'means for the implements and and means-for Y means 'to control the supply 'of a pressure meycliu'm to the cylinders for actionl on the pistons therein including separate selectorvalves controlling the passage of a'pressure medium to opposite ends' ofcertain cylinders, a 'masf 't'he" passage of a prestor valves, 'andcontrolrneans forfsai'cl master" Selector Valves, v e 6. An hydraulic operating control mecha- Vnism or earth lWorking implements, comprism0" ase'ries of istoA sand c lindersihavin suspension means 'for the Aiijnplements "andA` A means to control the supply f of `a pressure medium. tol the'cylinders for'action: on they 'l pistons therein` including separate selector' ffii pressure medium to oppositeJ a masterva'lve controllingthe passage. of a pressurefmedium Vto Aeither orboth vofthe sef lector valves, and control means ter ands'e'lector valvesl comprislng levers adapted to operate the master valve by movement in lcertain ldirections vand connected with the selector valves to move the latter in the same directions as the master valve and in' additional directions as well;

7. In a tractor grading machine, in combination, a supporting frame, a pair of'earth means for operating the latter including pressure mediumy operatingA devices and control means for a pressure medium directedto said -pressuremedium operated devices comprisA mechanism, and selector ing a master valve valve means, apumpand pressure reservoir with the` master valve mechafor saidmasyworking implements carried thereby and 6 i n Alfzmrew nism and selector valve means, the master vvalve meanscomprising valve, members and kassociated conduits arranged to relieve the `pumppressure .on the pressure medium op- Y ',erated devices ivhenfsaid pressure is not needc 'ed to deliver a pressure medium to the selectorvalvegand to cleliverfthe pressure medium discliar'ged from therpresfs'ure medium oper-vv t ated' devices to',` the reservoir.-

10 8. Means substantially as set forth in claim Y A7, wherein the selector valves are arranged to Y deflectthe passage of the pressure medium to the pressure operated devicesto control certain simultaneous and independent.actions- `oftliel.atter'fjf .A p 19.* In a tractor grading machine, a support'- ing frame, an earth working V implement supported thereo i `fluid pressure operated det vices for n'lovingY the implement, and valve mechanism to'l control the action of a fluid pressure medium on thesaid devices and inycliidingfafselector valve Vfor: one pressure op- -erating device tocontrolplural movements of thelatter` and Vmaster Avalve to control pas; sage'of the actuating pressure medium to the l sel'ector'valveQto relieve the pressurevon the saidoperating device when not needed, and' 'to control returnof discharged pressuremediuin from the operating-device under certain e conditions.4 A Y c 1 10. Ina tractor gradil'igmachinc of the flclass described, the combination with a main 'frfame 'and a Vplurality of" earth working implementsmounted thereon, of a control lever operable to VVcause either sefparate'for simul- H taneous raising and lowerin'gactions on the part of said iml'lemenfts".` *e l' i 'e In a tractor gradi'ng`- machine-ofthe Y l class described, the combination with a sup- 4o porting ramescarifierhancl a scrapi`ng, lc

rice7 ofa control lever on the supporting frame'operable to cause eitherseparate o r simultaneous raising and lowering actions on the part of the scariierv and scraping device. 12. In va tractor gradingr machine ot theV class described, the com'hii'iation withk ay main Y supportingV fran'ie', a scarifier and a sci-apnicr device,of a control leversconfmion to said scarifierfandA scrapingy device for controlling' i t t U'ci'faising andfloivcriiig actions onthe part of both the devices .h ,Y l 'In testimony iiihereof I aiix my signature.

LEO KINGANNON.

U10 um. meer; einen mi nes ein; i A y em sviev lessi ed? .dem qu' insioeiioe-i 

